1. Field of the Invention
The invention relates to the field of microfluidic devices and in particular to microfluidic pumps, pressure gauges and other components and to their method of operation.
2. Description of the Prior Art
Microfluidics is an exciting new technology that is establishing itself as an innovative practical tool in biological and biomedical research. Microfluidics offers the advantages of economy of reagents, small sample handling, portability, and speed. PDMS (polydimethylsiloxane) microfluidics in particular offers industrial scalability, parallel fabrication, and a unique capability for complex fluid handling schemes through fluidic networks containing integrated valves and pumps. However, microvalve actuation is still based on pneumatic control by macrovalves external to the devices themselves, while signal detection is generally done by optical microscopy, or some other macro means. By comparison to microfluidic technology itself, integration of electrical and optical devices into PDMS microfluidic chips is only at the dawn of its development. Herein lies an opportunity to produce a series of important devices for fluidic manipulation and signal detection.
The past ten years have witnessed the rapid development of PDMS (polydimethylsiloxane) microfluidic technology from the simplest of channels to an extended family of devices integrated by the thousands within the same chip. Such chips have emerged as the micro-scale hydraulic elastomeric embodiment of Richard Feynman's dreams of infinitesimal machines. PDMS microfluidics has been driven by applications from the beginning, with every advance being rapidly employed in devising solutions to specific problems. Thus it is no surprise that many exciting specialized chips have emerged to offer new capabilities, e.g. in protein crystallization, DNA sequencing, nanoliter PCR, cell sorting and cytometry, nucleic acids extraction and purification, immunoassays, and cell studies. After the development of pure microfluidic technology and the subsequent vigorous pursuit of its biological applications, it is becoming clear that the next generation of microfluidic devices would combine the fundamental technology with integrated electrical and/or optical systems for control and measurement. Such integration offers new analytical and functional capabilities, as well as true overall device miniaturization. A few steps in this new direction have already been taken, producing a capacitance cytometer, thermal cycler, and a spectrophotometer. Moreover, such devices can be arranged as independent but interconnected modules functioning within the boundaries of a single chip. Such chips with specific emphasis on devices for medical applications are called nanomedicine chips. They are anticipated to have the plumbing, electronics, temperature control, and functional capabilities to allow significant miniaturization of many of the current clinical laboratory machines.